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Re: Adaptive Image Element Proposal

From: Leif Halvard Silli <xn--mlform-iua@xn--mlform-iua.no>
Date: Fri, 31 Aug 2012 03:31:45 +0200
To: Laura Carlson <laura.lee.carlson@gmail.com>
Cc: Mathew Marquis <mat@matmarquis.com>, Adrian Roselli <Roselli@algonquinstudios.com>, HTML WG <public-html@w3.org>, "public-respimg@w3.org" <public-respimg@w3.org>
Message-ID: <20120831033145556841.bb26d9f9@xn--mlform-iua.no>
Hi Laura and Mathew,

Laura Carlson, Thu, 30 Aug 2012 14:05:45 -0500:
> On Thu, Aug 30, 2012 at 1:34 PM, Mathew Marquis wrote:

>>> Getting toolmakers to do that, however, 
>>> I know from experience is an uphill battle, but is at least 
>>> possible.
> 
> Agreed.

>>> It (aria-labelledby) is a bit more complicated. It also feels more 
>>> complicated than the replicated @alt, which doesn't mean you can't 
>>> use ARIA.
> 
> It is complex and vendors have raised concerns.
> http://rebuildingtheweb.com/en/aria-for-content-doomed/


Indeed. But we are not talking about that situation, are we? To add 
fallback content to elements in a WYSIWYG tool, is not a pleasant 
experience. One soon finds oneself fiddling with the mark-up code 
directly. To copy the content of on alt attribute and paste in another, 
would also not be simple. It seems simpler to add aria-labelledby and 
id attribute.

>> I agree. Now, likewise, I see no reason why `aria-labelledby` 
>> couldn’t be used here, but I’m not convinced we should make it a 
>> requirement.

No one has said that aria-labelledby should be a requirement. Only that 
it should a valid option.

> aria-labelledby does not make the image element valid. The Chairs
> decision found "to be redundant with other constructs".
> http://lists.w3.org/Archives/Public/public-html/2011Apr/0451.html


But they were not evaluating a situation where there would be 
one-to-one relationship between parent and child element. 

By the way: How is fallback supposed to be working in the picture 
element?  The draft points to HTML5 with regard to a definition of 
fallback. [1] However, in HTML5, there are at least 3 fallback models:

	* img: the element retains its role when we see the fallback
    * video/audio: we don't get fallback, even if the media format
      is unsupported.
    * object: if fallback steps in, then the object looses its default
      "role", and focus is given to the fallback instead.

One could say, that as long as picture element is not supported, then 
it is the object model that is operative. (And the duplicate alt model 
works OK - from users point of view - in that scenario.) But how should 
an without support for the mime type of the image react?

[1] 
http://dvcs.w3.org/hg/html-proposals/raw-file/tip/responsive-images/responsive-images.html#dfn-fallback-content

-- 
leif halvard silli
Received on Friday, 31 August 2012 01:32:22 UTC

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